Malicious PDF — malware analysis report

Static analysis result for SHA-256 cba78de909f13a3a…

MALICIOUS

PDF

87.3 KB Created: 2021-09-02 22:47:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7f1dd8c74e4af32fce2ba516b1ff8da7 SHA-1: 8a6b0555dd62c3e673ca21e3d2c7b3a5b8e19e1d SHA-256: cba78de909f13a3af473e88ba4819151a347779fe0f872b1a191728eaac5b8b0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to compromised websites and disposable hosting, characteristic of a link farm used for phishing or malware distribution. The presence of multiple external URIs and link farm heuristics strongly suggests the document's purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://inwebjor.ru/uplcv?utm_term=operating+system+technical+interview+questions+and+answers+pdf PDF link annotation
    • http://samurairamenbar.com/uploads/files/94729390079.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1611d19785c651---47727921595.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/1362d992cd7501048e98498b669ea434/dozikesonexijixikugufasil.pdfIn PDF document text
    • https://arbormaster.net/uploads/files/82855504684.pdfIn PDF document text
    • https://noticky.net/akce/fotky/file/70385839444.pdfIn PDF document text
    • https://archltginc.com/wp-content/plugins/super-forms/uploads/php/files/8d90ad7b4a9f40974cc913864b27a1d9/pibupi.pdfIn PDF document text
    • https://movingalpsfoundation.ch/userfiles/file/17636398425.pdfIn PDF document text
    • http://dentherapia.hu/files/file/46653756299.pdfIn PDF document text
    • http://matras-devison.com/upload/file/mugutebexojigizisutoxa.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b0d7e80bb03---82853289707.pdfIn PDF document text
    • http://mspchicagolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rababupifamuregugolufimar.pdfIn PDF document text
    • http://ramenzoni.eu/userfiles/files/morupe.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/7a6806252c952af0e35f8a460804ebe5/2475570025.pdfIn PDF document text
    • http://eot.mn/uploads/userfiles/files/tibevotojatuw.pdfIn PDF document text
    • http://hong-tour.com/FileData/ckfinder/files/20210814_3C4BF1A3C01AF5F1.pdfIn PDF document text
    • http://ieltsadd.ir/cache/fck_files/file/4396194974.pdfIn PDF document text
    • https://108pizza.pl/uploads/userfiles/files/68641530126.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16094ba32bdedd---wopev.pdfIn PDF document text
    • http://vitalenzyme.com/uploads/fckupload/file/93558816012.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/11508993070.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/56261871761.pdfIn PDF document text
    • http://www.climatisur.com/ckfinder/userfiles/files/53857234631.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/34ad6d5992ee22dcf7924f6a802f8da1/gexoxixumemozip.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/e28e16e683f4aaed734f4af79d81b699/xatezaweposoponemominesak.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED77 11604 bytes
SHA-256: 4f10beee49e41ca094ebfbd6d46b50db42baa599a181f93a8ec4f75a6a53ce87
font_01_sfnt_off00010868.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10868 18004 bytes
SHA-256: c645d225d670546d7d86ddec0696417e6eda822b8a2f0c15937d5c5bd1cefb2c
font_02_sfnt_off0001369d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1369D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1